1. Field of the Invention
The present invention relates to a resin substrate combined structure. A “resin substrate combined structure” as referred to herein means a structure in a form in which a plurality of resin substrates are combined.
2. Description of the Related Art
There is a case in which a flexible resin substrate such as a resin multilayer substrate is disposed in a narrow casing and thus used or a plurality of resin substrates are combined together and thus used for high-density interconnect. When disposing a resin substrate in a casing, there is a case requiring disposing the resin substrate such that the resin substrate leaves a necessary space. Furthermore, there is a case requiring disposing a plurality of resin substrates simultaneously in a limited space. In these cases, in order to avoid an electromagnetic effect or dispose the substrates with the electromagnetic effect considered, a technique to control a spacing between the plurality of resin substrates, as desired, or a technique to maintain the spacing is required. Japanese Patent Laying-Open No. 2007-134473 describes a configuration in which what is referred to as a flexible circuit board is bent and the bent portion has an inner surface with a shape retaining member disposed thereon.
The technique described in Japanese Patent Laying-Open No. 2007-134473 can retain a single flexible circuit board's bent shape, however, in Japanese Patent Laying-Open No. 2007-134473 a case in which a plurality of flexible circuit boards are adjacently disposed in a small space is not assumed. When a plurality of flexible circuit boards having the configuration described in Japanese Patent Laying-Open No. 2007-134473 are adjacently disposed, their mutual spacings cannot be controlled and their mutual distances may undesirably vary or they may contact each other. In such a case, it is believed that variation in electrical characteristics is caused by electromagnetic interference. Furthermore, there is also a possibility that an undesirable bending stress will act and an interconnect may be disconnected.